Electric keyboard for tape perforator



March 7, 1961 Filed Oct. 3, 1957 H. L. JOHNSTON 2,973,810

ELECTRIC KEYBOARD FOR TAPE PERFORATOR 2 Sheets-Sheet 1 INVENTOR.

ATTORNEY M arch 7, 1961 JOHNSTON 2,973,810

ELECTRIC KEYBOARD FOR TAPE PERFORATOR Filed 001;. 5, 1957 2 Sheets-Sheet 2 IN V EN TOR.

,1 1 '4 4 TORNEY ELECTRIC KEYBOARD FOR TAPE PERFORATOR Harold L. Johnston, 2212 Huntleigh Drive, Oklahoma City, Okla.

Filed Oct. 3, 1957, Ser. No. 688,038

Claims. (Cl. 234-125) The present invention relates to tape perforators and has reference more particularly to a kit-modification or means for converting the manually tripped latch assembly to an electromagnetic tripping action.

Tape perforating machines are used extensively at the present for punching a code in a control form or paper tape, which is thereafter fed through an operating unit to automatically actuate a Linotype machine for casting type slugs.

The term tape perforator as used herein, refers to a self-contained motor-driven portable unit which includes a set of keys, key levers, selector bars, perforating and counting mechanism, and end of line or justification indicating mechanism. The perforating and counting mechanism of the perforator is controlled by a keyboard, arranged similarly to that of a typewriter, and by means of which combinations of holes, corresponding to the selections of a code, may be punched in the control form or paper tape. The code is cut in the paper tape by cam actuated punching mechanism driven by a high'speed main shaft which revolves one-half revolution when tripped by manually depressing one of the keys for disengaging a latch assembly. The manual tripping ofthe latch assembly necessarily sets up an excessively heavy, long stroke for each key, and is very objectionable to speedy operation. Included within the linkage sequence of tripping the latch assembly is a dead link in the form of a floating trip plunger, resulting in a slugg sh resetting of the latch assembly which is operating against friction caused by the high speed shaft, causing frequent drop-outs or failures of the punching sequence. This requires an unnecessary Waste of time to rub out the line of code punched tape and to repunch the word or words in order to insure a safe line count to fill the line slug in the Linotype or casting machine.

It is therefore the principal object of this invention to provide a device which may be connected to a conventional tape perforator for converting the manually operated keyboard to electric operation. 1

I have found, in testing the present invention, that an experienced operator can increase his number ofline's punched approximately 1,000 lines per day when using my device as compared to a conventionally operatedtape' perforator. This is roughly a twenty-five percent increase in output efficiency.

It is therefore a similarly important object to provide a device for aiding the operator in tripping a tape perforator which will materially increase the linage produced thereby.

Another object is to provide a device for converting a manually operated perforator keyboard so thatthe effort required to depress the keys will be materially reduced, thereby resulting in a light touch keyboard.

Converting the keyboard of a tape perforator to a magnetic tripping action normally results in at least two serious and undesirable characteristics which must be overcome to render the action of the perforator acceptable. First, the universal bar has a tendency to bounce Patented Mar. 7, 1961 or rebound after being depressed by a key lever which results, in many instances, in a second setting and punching of the tape in the code justselected. Secondly, due to the rapid action of the magnetic tripping action, space counts'set up by the action of depressing the space bar are frequently notrecorded by the justification counter, resulting in unjustified or long lines.

Another important object of the present invention is to provide a means, in connection with a magnetic tripping device for a tape perforator, for dampening the universal bar and registering each and every space count.

Another important object of this invention is to provide a low cost, yet highly efficient, kit-modification for tape perforators.

An additional objectv is to provide a device of this'class which may be connected to any conventional aiternating current power supply usedfor driving the motor.

Another object is to includea circuitby which a repeat operation may be performed by simultaneously depressing the repeat key and any other selected key.

Another object is to dampen the bounce or rebound of the universal bar and prevent the possibility of double letters being spuriously set up by an unwanted contact actuation. V I I Another object of the invention is to prevent the loss of a space count resulting in unjustified line counting.

A further object is to provide a device which is immediately recharged or reset for a subsequent operation each time the electro-magnet is energized. p

Still another object is to provide a. device of this class which has the versatility of being used with any conventional or electronic power supply capable of producing either direct or pulsating current. h 4

The present invention accomplishes these and other objects by providing a 'rectiiierand an electric wiringicircuit in combination with a conventional tape perforator.

An electro-magnet is. operatively connected to the latch assembly for tripping the latter when theelectro-ma'gnet is energized. Switch means is con'uected 'to t e frame and actuated by the moverne'ntof the universal bar link. A condenser is interposedbetween the reetifierand the electro-magnet for pulsatingly energizing the ele'ct'ro- Y magnet. A second switch is connected 'to the circuit and is closed by operation of the repeat key for by-passing the condenser'circuit and maintaining the elec'troanagnet energized to permit a continuous or repeat operation of the punching mechanism;

Other objects will be apparent from ,scription when taken *in conjunction with the accompanying two sheets of drawings, wherein:

Figure 1 is a p'er's'pectivefview of a conventional tape perforator with thepreserit invention installed thereonj Figure 2 is a fragmentar' 'y front elevational view of the I conventional latch assembly and component parts, showing the stopped position by solid lines and illustrating in dotted lines the activated position;

Figure 3 is a view similar-to 2, illustratingthe manner in which the present invention operates thelatch assembly; a a 1 Figure 4 is afragmentary bottom plan view of the forward portion or keyboard end of the pcrforator, illustrating the connection between the universal bar link and the switch means; I I

Figure 5 is a fragmentary side elevation-a1 view, p-artly in section, of a single key,link-and universal bar;

Figure 6 is a fragmentary sectionalviewof the uni versal bar, illustrating a fragment of its support 'in-eleva tion and the relative positionofthe rebound *dampener p; Figure 7 is a vertical cross sectional view taken substantially along line 7-7 "of 6;

thefolloyving as,

Figure 8 is a perspective view of the repeat key and a fragment of the non-repeat latch;

Figure 9 is a fragmentary perspective view of one end of the repeat key link, and illustrating diagrammatically its association with an electric switch;

Figure 10 is a wiring diagram; and,

Figure 11 is a fragmentary perspective view of the in termediate pawl latch and its component parts.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral 15 indicates, as a whole, a conventional tape perforator including a frame 16, motor 17, a motor-driven main shaft 18, tape reel container H, a set of keys and links 20, space bar 21, a repeat key 22, universal bar assembly 23 (Fig. 2), and counting scale 24.

Conventional operation of the perforator will be more clearly understood by referring more particularly to Fig. 2, wherein the solid line position of the component parts illustrated indicate a stopped or latched position. A stop lever latch 30 is pivotally mounted horizontally on the frame 16 by a pin 32 below the main shaft 18. A stop lever cam 34, having laterally projecting stop lugs 35 spaced 180 apart, is rigidly connected axially to the main shaft. A stoplever 36, pivotally mounted on the frame for horizontal swinging movement, extends between the stop lever cam 34 and the stop lever latch 30. The upper end of the stop lever 36 is provided with a roller 38 which rides on the surface of the cam for pivoting the stop lever when the cam is revolved by the main shaft. A depending extension 40 of the stop lever normally is engaged in stop position with a shoulder 42 on the upper surface of the top lever latch 39. A lateral projection. 44 on the stop lever engages with one of the stop lugs 35 on each half revolution of the cam 34. A spring 46, connected with the stop lever latch 30, pivots the latter and urges the shoulder 42 in contact with the stop lever projection 40.

The universal bar assembly 23 includes a universal bar 48 which is mounted between guides 50 (Fig. 6) adjacent each of its ends for vertical movement and is actuated for such movement by depressing one of the keys and associated link which is in contact with the upper edge of the universal bar (Fig. 5). A pair of Y- levers 52 and 53 are pivotally connected on the rearward side of the universal bar 48 by pins 54 to a pair of rectangular supports 52A and 53A, respectively, rigidly mounted, transversely of the universal bar 48, on a horizontal portion of the frame 16. A pair-of downwardly open slots 48B and 48C, formed in the universal bar 48, loosely receives the respective supports 52A and 53A. A universal bar link 56 extends between and is pivotally connected to the respective depending ends of the Y-levers 52 and 53 by pins 58. When the universal bar is depressed by a key lever, the Y-levers 52 and 53 are pivoted counter-clockwise, as illustrated in dotted lines, thus moving the universal bar link 56 toward the right, as viewed in Fig. 2. A spring 60 is connected at one end to a post carried by the frame 16 and is connected at its opposite end to the left end of the universal bar link 56, as viewed in Figs. 2 and 3, for thepurposes of normally maintaining the universal bar and universal bar link in the position shown by solid lines. As viewed in Figs. 2 and 3, the left end prong 62 of the Y-lever 53 extends forwardly under and supports the lower surface edge of the universal bar 48, while the right end prong 64 contacts the upwardly disposed end of a vertical stop 66 adjustably carried by the frame 16. The left end prong 68 of the Y-lever 52, as seen in Fig. 2, similarly extends forwardly under and contacts the lowermost surface edge of the universal bar 48 in supporting relation, while the right end prong 70 thereofcontacts the lowermost end of a vertically disposed trip-off plunger 72, for the purposes which will presently be explained.

Thus, it may be seen that the spring 60 urges the universal bar link 56 toward the left, as seen in Fig. 2, urging the universal bar 48 upwardly, being supported by the Y-lever prongs 62 and 68, until the Y-lever prong 64 is in contact with the stop 66, as is illustrated in solid lines. The trip-off plunger 72 is slidably supported vertically by a plunger guide 74 carried by the frame 16. The trip-off plunger 72 extends between the /-lever prong 7t) and the depending end of an adjusting screw 75 carried by the end portion of the stop lever latch 30 opposite the shoulder 42. Thus, when any one of the keys, for example the key 76, is manually depresed, its associated link 78, being in contact with the universal bar 48, forces the latter downwardly. Downward movement of the universal bar 48, in contact with the lugs 66 and 62 of the Y-levers 52 and 53, respectively, pivots the latter about their respective pivot pin 54 and moves the universal bar link 55 toward the right, as viewed in Figs. 2 and 3. This action causes the Y-levcr prong 70 to lift the trip-off plunger 72 for pivoting the stop lever latch 30, releasing the stop lever extension 40 from contact with the stop lever latch shoulder 42. A spring 30, connected with the stop lever 36, then pulls the stop lever projection 44 to the right or counterclockwise, as seen in Fig. 2, out of contact with the adjacent cam stop lug 35, thus permitting the cam to revolve in the direction shown by the arrow 82. A non-repeat latch 84 is carried by the pin 32 above the stop lever latch 30 for vertical pivoting movement. One end of the non-repeat latch extends laterally beyond the stop lever extension 40 and is provided with a depending shoulder 86 disposed above the shoulder 42. A spring 37 extends between the end of the non-repeat latch opposite the shoulder 86 and the adjacent end portion of the stop levcr latch 30 for urging the non-repeat latch in a clockwise direction, as seen in Fig. 2. When the cam 34 is released and starts its clockwise revolution, the stop lever roller 38, riding upon the surface of the cam, pivots the stop lever 36 clockwise so that the projection 44 contacts the previously oppositely disposed cam lug 35, thus permitting the cam to revolve only one-half revolution each time a key is depressed. Simultaneously with the above action, the non-repeat latch is urged downwardly, locking-up the stop lever 36 in this new position by the depending shoulder 86 engaging the projection 40. Upon releasing the depressed key 76, the spring 46 pivots the stop lever latch 30 back into position so that the shoulder 42 disengages the non-repeat and stop-lever latches, and again engages the stop lever depending projection 40, while the spring 60 returns the universal bar link 56, universal bar 48, and Y-levers 52 and 53 to their inactivated position. Depressing the key 76 sets up a coding sequence. not shown, which is simultaneously punched in the tape 83. 'When an error has been made in the code punching sequence, the coding is rubbed-out by completely punching the tape '83, since full punching does not actuate the Linotype machine through which the tape is subsequently run. This rub-out action is accomplished by depressing the repeat key 22, pivotally carried by the frame 16, so that its link or lever portion 22A, which extends below, an extension 92 on the non-repeat latch 84 (Fig. 2), contacts the extension, thus lifting the nonrepeat latch so that the non-repeat latch shoulder 86 is held out of the contact with the stop lever projection 40, when the rub-out key, not shown, which sets up a code punching sequence for completely punching the tape 83, is depressed simultaneously with the repeat key 22. thus the stop lever latch 30 is pivoted downwardly for permitting the cam 34 and main shaft 18 to revolve con tinuously, and completely punch the tape.

The above description is conventional in the manual operation of conventional tape perforators of this class. and forms no part of the present invention other than to c reals set forth a workable combination with which the instant invention is designed to be used. I

In carrying outthe invention a tripping electro-magnet 89 comprising a pair of substantially vertically disposed coil magnets 90., each having a soft iron core 91, are mounted on a frame 92, which is in turnmounted on the. perforator frame 16 adjacent the free end 93 of the stop lever latch 30 (Fig. 3). An armature 94'is pivotally connected at one end to the magnet frame 92 and extends in. closely spaced relation across the upper ends of the magnet cores 91 and. projects laterally toward and terminates in spaced relation above the end 93 of the stop lever latch 30. The armature 94 is normally urged upwardly away from the magnet cores 91 by a spring 95 extending between its free end portion and the frame 92. A set screw 96, threadedly carried by thefrarne 92, limits the movement of the armature away from the cores 91. An upstanding projection 97 is rigidly connected to the free end. 93 of the stop lever latch and is terminated adjacent the free end, of the armature 94. An adjusting screw 98, threadedly carried by the. free end of the armature 94, is positioned to contact the upwardly dis.- posed end of the projection 97. Thus, when energized in the manner explained hereinbelow, the magnets 90 attract the armature 94 moving the latter downwardly and simultaneously pivoting the stop lever latch 30 to release. the shoulder42 from engagement with the stop lever extension 40 in combination with a sequence of operations more fully explained hereinbelow.

Referring more particularly to Fig. 1, the numeral 100 indicates, as. a whole, a conventional voltage doubling, 1 00 milli-ampere selenium rectifier unit which is connected-to theperforator frame 16. The rectifier 100 is connected with the source of electrical energy such as the alternating current which operates the motor 17. The rectifier 100 is shown diagrammatically in Fig. andv includes a 60 milli-ampere holding circuit and a condenser 101 which sets up a pulsating current. for energizing the magnets 90.

Switch means102 (Figs. 4 and 10) is connected to the lower surface of the frame 16 adjacent the righthand end portion, as seen inFig. 4, of the universal bar link 56. The switch means comprises a pair of stationary contacts 103 and 104 disposed on opposing sides of a central movable, contact 105. -Wiring 106 connects one output side ofthe rectifier 100m the contact 103, while a conductor 107-. connects the opposite output of the rectifier to thecoils 90 in. series which are in turn connectedtovthev contact 104-by a conductor 108. A conductor109-connects the movable contact 105 to. the wire 107. The condenser 101 isinterposed in the wire109 between the contact 105 and the wire 107 in series. with the source ofelectric energy, when. the contacts 103 and. 105 are closed, and in series with the coils 90 when the, contacts 104 and 105 are closed. The movable contact 105 is normally in contact with the .contact103, thus rendering the condenser 101 charged. Movement of the contact 105 away from the contact 103 andmaking connection with the contact 104 c0mpletes a circuit from the condenser 101 through the coils 90 and discharges the condenser 101 through thecoils 90 energizing the latter and lowering the armature 94 in a snapping action which trips or releases the stop lever latch 30 from engagement with the stop lever 36.

Movement of the contact 105 to discharge the condenser 101 through the coils 90 is accomplished in the following manner. An arm 110 is rigidly connected at one end to the end portion of the universal bar link 56 adjacent the switch means 102. The free end of the arm 110 is disposed adjacent the movable contact when the. universal bar link 56 is in rest position. Thus, when anyone of the keys 20 is depressed, the universal bar 48is moveddownwardly, pivoting the Y-levers 52 and 53, moving the universal bar linked toward the right, as seen in Fig. 3, and forcing the arm against 6. the va le. ated. 1. 5.. wanin the no m y, osed. contacts 1 03 and 105 and fo-rf'rnoving the. lat ter into con; wi e ta t P i t. 10.4 o c mp e e hecir leased the universal bar 48 d the. universal link 56 .arc. returned to their position of rest by the tension of the spring 60, breaking tlie circuit between the contacts 105.

and 104 and making contact between. the points 105 and 103, whereby the condenser is immediately recharged, thus. completingthe cycle of discharging the condenser 101 through the coils.

In the arrangement illustrated in Fig. 3, the lower. end. portion of the trip-off plunger 72 is cut off, thus eliminating the mechanical linkage connection between thef Y- lever prong and the, stop lever latch 30. The upper end portion of the trip-off plunger 72 is retained in place within the plunger guide 74 for the purposes of adjustably positioning the stop lever latch 30 by means 1 of the adjusting screw 75. The nonrepeat latch 84 is preferably removed fromthe pin 32 in this arrangement. I

Thus, itmay be seen that when a key 20 is depressed, th e condenser 101 is discharged through the coils which. trips or releases the stop lever latch shoulder 86, from engagement with the stop lever projection 40, permitting the cam 34 torevolve as explained hereinabove, The cam surface 35 pivots the stop, lever latch .30 back into latching position to be engaged by the shoulder 86 as the spring 46, urges the stop lever latch. 30 upwardly against the projection40. It seems obvious that more than one.

tripping of the stop lever latch 30 cannot result from holding any one key, depressed since the condenser 1 .1. is

discharged through thecoils 90 andcannot berechargedf until contact is again-made with the point 103.

Since it requires less pressure on any one of the keys 20 to move the universalbar 48' and its component parts i for actuating the" contact than does the mechanical tripping action described hereinabove, the centralloyver portion of the universal bar 48 is removed, as by cutting out a portion thereof, as may beseen by a comparison oft: This lightens the weight of the altered universal bar 48A approximately one ounceand'permitss Figs. land 3.

the tension of the universal'bar link spring 60 to be similarly reduced approximately one ounce] This resultsin a lighter touch of the. keyboard.

As a result of the rapid action of magnetic tripping.

the universal bar 48A will have a tendency to bounce or rebound downwardly, after beingreleased and drawn upwardly within its guide slot and forciblycontacting.

the upper limit of'its movement. Such bouncing or rebounding downwardly frequently causes the universalbar link 56 to move its ar-m a sufficient distanceto make an unauthorized contact between the points 105.

and 104 resulting in double punching of the tape 83 in the character code selected by the key previouslydepressed.- This objectionis overcome by securing a rela-.

tively small, preferably plastic, stop'111 withinthe unia versal bar guide-slot- 112 above each respective end por tion of the universal bar-48A and adjacent the upper limit of the slot where it is retained by a clamp'1 13 (Figs. 6. and 7). Thus, a lightened universal bar 48A and a weaker spring 60 results in a reduced tendency of the universal bar to rebound and the stop 111 cushions the force of the upwardly traveling bar and eliminates rebounding. i

It is necessary, however, to include a means for-effecting a repeat action of releasing the stop lever 36 in order to completely punch thetape 83 to rub-out errors as explained hereinabove.- This is accomplished'by securing a second switch 115 to the perforatorframe 16 adjacent and abovethe free end of the repeat key lever-22A One terminal of this switch 115 is;

(Figs. 9-and 10). connected by a wire 116 to the rectifier 100, and the. opposite terminal of the switch 115 is connected te the movable contact 105by ajwire Thus, it maybe any one'cf the keys 2 0 is depressed, a-

seen that, when circuit is completed between the contacts 105 and 104 as explained hereinabove, and simultaneously depressing the repeat key 22 pivots the repeat key lever 22A which closes the contacts of the switch 115, permitting a current to flow from rectifier 100 over the wire 116, through the switch 115, contacts 105-104, and coils 90, by the wires 117, 108 and 107, thus keeping the coils energized and the stop lever latch 30 released from engagement with the stop lever 36. This permits the shaft 18 to continuously revolve the cam 34 until the repeat key is released to interrupt the circuit and de-energize the coils by breaking the contacts of the switch 115.

Any form of electromagnetic tripping of the tape perforator tends to create the susceptibility of losing, or the failure to record one or more space counts on the counting scale 24 which results in an objectionably long line. When the space bar 21 is depressed, in addition to setting up the combination in the perforating mechanism as when any one of the keys 20 are depressed, an extension 120 on the space bar lever 121 moves the intermediate pawl 122 by means of the intermediate pawl latch 123, thus actuating the counting pointers 124 through linkage not shown (Fig. 11). The loss of a space count results in the space function levers, not shown, in not resetting quickly enough on the upward release movement of the space bar lever 121. It may be seen from Fig. 11 that one end of the intermediate pawl 122 contacts a shoulder 125 on the intermediate pawl latch 123. To accurrately record each space count, the end of the intermediate pawl 122 must be released from the shoulder 125 when the space bar 21 is depressed. To facilitate this requirement, the latching surface width or shoulder 125 is reduced from .040 to .018".

, Operation A typical operating cycle of the modified tape perforator is as follows: When the keys 20 and space bar 21 are at rest the contact points 103 and 105 of the main switch 102 complete a circuit from the rectifier 100 across the tripping condenser 101 for charging the latter. Any one of the keys 20 may be fully depressed, moving the universal bar 48A downward, pivoting theY-levers 52 and 53 thus moving the universal bar link 56 toward the right, as viewed in Fig.3, causing the arm 110 to break the contact between the contact points 103 and 105 and to make contact between the points 105 and 104 and discharge the condenser 101 through the coils 90, thus energizing the latter with a single pulse of current which moves the armature 94 downward in a snapping action and pushing the stop lever latch shoulder '86 'out of engagement with the stop lever extension 40 by means of the stop lever latch projection 97. This releases the cam 34 and permits the latter to revolve with the main shaft 18, while simultaneously punching the desired character code in the tape as selected by the depressed key. The cam 34 revolves only one-half revolution as is conventional in mechanical operation of the perforator. Since the tripping action of releasing the stop lever 36 by the armature 94 is an instantaneous one-pulse action, the armature is returned immediately to its at rest or unactuated position, which allows the stop lever latch 30 to return to its normal at rest position engaging the stop lever projection 40 and thus preventing further revolution of the cam 34 which would result in a further or second undesired punching of character codes in the tape 83.

When the depressed key is released the universal bar 48A and the universal bar link 56 are returned to their respective at rest positions, thus breaking the contact between the points 105 and 104 and restoring the contact between the points 105 and 103 to complete the circuit with the rectifier 100 and recharge the condenser 101 to complete the cycle.

A complete cycle of repeat-action is accomplished-in the following manner: The repeat key 22 is fully depressed closing the contacts of the switch 115 for setting-up a 60 milli-ampere circuit which will flow through the coils 90 when a selected key is depressed in co-operation with the repeat key. Depressing the selected key simultaneously with the repeat key 22 completes the circuit through the coils 90 by closing the contact points 105 and 104 which maintains the coils energized and holds the armature 94 in contact with the stop lever latch 30. This permits the main shaft 18 to revolve the cam 34 continuously and repeatedly cut selected character code in the tape 83 as long as the two keys are depressed. When the keys are released, contact is again made between the points 105 and 103, the condenser 101 is recharged and ready for the next sequence of normal operation.

It may be desirable to use direct current where the same is available. This may be done by omitting the rectifier 100 and the switch means 115. The non-repeat latch 84 and spring 87 are retained in their conventional positions. The middle or movable contact 105 and tripping condenser 101 is eliminated. A typical cycle of direct current operation is as follows: A selected key is depressed to actuate the universal bar link 56 in closing the contact point 103 with the point 104 to complete a circuit through the magnet coils 90, thus disengaging the stop lever 36 from the stop lever latch 30 for the punching operation, as disclosed hereinabove. However, in this type of installation, the non-repeat latch 84 performs its normal conventional manual operation function in preventing the punching of more than the single selected character code in the tape 83. When the depressed key is released the universal bar 48A and link 56 are returned to their respective at rest positions, thus breaking the circuit through the coils, releasing the armature 94, releasing the disengaged stop lever latch assembly 30, and restoring the component parts of the next depression of a selected key.

A typical repeat action operating cycle, when using direct current follows: The repeat key 22 is depressed which holds the non-repeat latch 84 in an inoperative position as disclosed for the manual operation of the perforator hereinabove. A selected key is depressed, closing the contact points 103 and 104 to complete a circuit through the coils 90, forcing the stop lever latch 30 out of engagement with the stop lever 36 and permitting the main shaft 18 to continuously revolve the cam 34 and punch the selected character coding in the tape. As long as a key is held depressed in cooperation with the repeat key, the repeat action will be operative. When the selected key is released the electrical circuit is broken through the coils and the repeat action stops.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claims.

I claim:

1. In a control form perforating apparatus having, a frame, a motor mounted on the frame, a motor driven shaft carried by the frame, a motor driven control form holder apparatus carried by the frame, a motor driven control form punching means, a set of keys, key levers and selector bars for setting up a control form punching code in the punching means, a stop lever and a stop lever latch, universal bar means movable downwardly by the key levers for releasing the stop lever and permitting actuation of the punching means by the motor driven shaft when said stop lever is released, an improvement which comprises: a rectifier carried by said frame and connected with a source of electrical energy; an electromagnet carried by said frame in contact with said stop lever latch for tripping the latter when said electromagnet is energized; electric switch means carried by said frame adjacent one end of said universal bar means; electric wiring connecting said rectifier to said electro-magnet and said switch means; a condenser connected with said rectifier and said switch means in series with said elecire-magnet; said switch means including a pair of normally closed contacts and a pair of normally open contacts, said closed contacts completing a circuit through said condenser; and an arm carried by said universal bar means for opening said closed contacts and closing said open contacts of said switch means when one key of said set of keys is depressed, thereby interrupting the circuit from said rectifier through said condenser and closing a circuit from said condenser through said electro-magnet for energizing said electro-magnet and tripping said stop lever latch.

2. In a control form perforating apparatus having, a frame, a driven motor mounted on the frame, a motor driven shaft carried by the frame, a motor driven control form holder apparatus carried by the frame, a motor driven control form punching means, a set of keys, key levers and selector bars for setting up a control form punching code in the punching means, a stop lever and a stop lever latch, universal bar means actuated by the key levers for releasing the stop lever and permitting actuation of the punching means when said stop lever is released, an improvement which comprises: a rectifier carried by said frame and connected with a source of electrical energy; an electro-magnet carried by said frame and operatively connected to said stop lever latch for releasing the latter when said electro-magnet is energized; electric switch means carried by said frame adjacent one end of said universal bar means; electric wiring connecting said rectifier to said electro-magnet and said switch means; a condenser connected with said rectifier and said switch means in series with said electro-magnet, said switch means including a pair of normally closed contacts and a pair of normally open contacts, said closed contacts completing a circuit through said condenser; and an arm carried by said universal bar means for opening said closed contacts and closing said open contacts of said switch means when one key of said set of keys is depressed, thereby interrupting the circuit from said rectifier through said condenser and closing a circuit from said condenser through said electro-magnet for energizing said electro-magnet and tripping said stop lever latch.

3. In a control form perforating apparatus of the class described having, a frame, a control form punching means, a set of keys including a repeat key, key levers and selector bars for setting up a control form punching code in the punching means, a stop lever, a stop lever latch, universal bar means actuated by the key levers for permitting actuation of the punching means when said stop lever is released, an improvement which comprises: a rectifier carried by said frame and connected with a source of electrical energy; an electromagnet carried by said frame and operatively connected to said stop lever latch for releasing the latter when said electro-magnet is energized; a first switch means carried by said frame adjacent one end of said universal bar means; electric wiring connecting said rectifier to said electro-magnet and said first switch means; a condenser connected with said rectifier and said first switch means in series with said electro-magnet, said switch means including a pair of normally closed contacts and a pair of normally open contacts, said closed contacts completing a circuit through said condenser; an arm carried by said universal bar means in contact with said first switch means for opening said closed contacts and interrupting the circuit from said rectifier through said condenser and completing a circuit between said electro-magnet and said condenser when one of said set of keys is depressed; and a second normally open switch means interposed between said rectifier and one contact of said normally open contacts of said first switch means adjacent said re peat key for completing a circuit, when said second switch means is closed, between said rectifier and said electro-magnet when said repeat key is depressed simultaneously with one key of said set of keys and maintaining said electro-magnet energized.

4. In a control form perforating apparatus of the class described having, a frame, a control form punching means, a set of keys, key levers and selector bars for setting up a control form punching code in the punching means, a stop lever, a stop lever latch, horizontally disposed universal bar means slidably carried by said frame and actuated by said key levers for vertical reciprocating movement and releasing said punching means when said stop lever latch is released, an improvement which comprises: a rectifier carried by said frame and connected with a source of electrical energy; an elect-ro-magnet carried by said frame and operatively connected to said stop lever latch for releasing the latter when said electromagnet is energized; switch means carried by said frame adjacent one end of said universal bar means; electric wiring connecting said rectifier to said electro-magnet and said switch means; a condenser connected with said rectifier and said switch means in series with said electromagnet, said switch means including a pair of normally closed contacts and a pair of normally open contacts, said closed contacts completing a circuit through said condenser; an arm carried by said universal bar means and selector bars for setting up a control form punching code in the punching means, a stop lever, a stop lever latch, horizontally disposed universal bar means slidably carried by said frame and actuated by said key levers in a vertical reciprocating movement for releasing said punching means by the release of said stop lever, an improvement which comprises: -a rectifier carried by said frame and connected with a source of electrical energy;

an electro-magnet carried by said frame and operatively 7 connected to said stop lever latch for releasing the latter when the electro-magnet is energized; a first switch means carried by said frame adjacent one end of said universal bar means; electric wiring connecting said rectifier to said electro-magnet and said first switch means; a condenser connected with said rectifier and said switch means in series with said electro-magnet, said first switch means including a pair of normally closed contacts and a pair of normally open contacts, said closed contacts completing a circuit through said condenser; an arm carried by said universal bar means in contact with said first switch means for opening said closed contacts and closing said open contacts and completing a circuit between said electro-magnet and said condenser when one of said set of keys is depressed; a second normally open switch,

References Cited in the file of this patent UNITED STATES PATENTS 2,077,600 Watson Apr. 20, 1937 2,222,631 Potts Nov. 26, 1940 2,223,163 Boeker Nov. 26, 1940 2,346,267 vMills et a1. Apr. 11, 1944 2,607,421 Anderson Aug.-19, 1952 

